Webmin Firewall - Virtualmin Firewall - ConfigServer Security & Firewall - CSF

I like Virtualmin web hosting control panel (Free version) to host my sites.

The important part to secure your server is Firewall security. Here I like CSF as the best one.

Also, I like to use my control panel at a custom port for further security. You know the custom port 49152 to 65535 is not assigned, controlled, or registered. So it is better to select a custom port from this range 49152-65535.

I personally like to use 51000 as Webmin custom port, and 52000 as Usermin custom port.

Debian Linux

So, my recommended necessary port to configure in Firewall is the following:

Incoming: 25,80,443,465,587,993,995,51000,52000

Outgoing: 21,22,25,53,80,123,443,465,587

1) Start installing the CSF first

cd /usr/src
rm -fv csf.tgz
wget https://download.configserver.com/csf.tgz
tar -xzf csf.tgz
cd csf
sh install.sh

2) Check and remove if the nftables installed

apt-get remove --auto-remove nftables
apt-get purge nftables

3) Make sure the iptables is installed

apt-get install iptables

4) Check the necessary perl is installed

apt-get install libwww-perl

Finally, install/activate the csf webmin module:

  Webmin > Webmin Configuration > Webmin Modules >
  From local file > /usr/local/csf/csfwebmin.tgz > Install Module

Configure the firewall settings.